The invention concerns an impactor for the analysis of a carrier gas enriched with suspended particles, with a classifying nozzle unit having at least one classifying nozzle and with an impact plate, the impact plate being formed as an oscillating crystal and the resonantly oscillating, mass-sensitive element being secured in an impact plate holder.
The invention also concerns a method for characterizing a carrier gas enriched with suspended particles, the carrier gas enriched with suspended particles being conducted in an impactor through a classifying nozzle onto a resonantly oscillating, mass-sensitive element acting as an impact plate in such a way that, as from a prescribed mass, suspended particles are deposited in a depositing process on the resonantly oscillating, mass-sensitive element, and the mass of the suspended particles deposited on the resonantly oscillating, mass-sensitive element being determined electronically during the depositing process and/or between two depositing processes.
Such an apparatus and such a method are known, for example, from EP 1 957 955 B1, in which the oscillating crystal is held at three points arranged rotationally symmetrically in relation to one another about its normal axis of symmetry. The use of an oscillating crystal offers the advantage over films for receiving the deposited suspended particles that measurement of the deposited mass is possible without removal of the impact plate.
The invention is based on the object of improving the functional properties of an impactor.